Testing the hearts of athletes to protect their lives

Everyone has heard the stories: the fit 20-something who drops dead in the middle of a marathon, the high school football player who, without warning, dies during practice. While rare, the stories of sudden death among young athletes strike fear into the hearts of parents everywhere.

In an effort to protect against sudden death in athletes, researchers at the School of Medicine have begun a voluntary program to conduct advanced routine heart testing of all the university's student athletes. Starting with the entire football team in September, researchers completed elective electrocardiograms, known as ECGs, on all 800 of the university's athletes from golfers to swimmers to cross-country runners. Heart ultrasounds are up next.

In the United States, advanced routine heart testing of athletes is a controversial issue. It's required of many pro athletes but not for college or high school athletes. Preparticipation requirements are usually limited to physicals and medical history. In general, the thinking goes, heart testing is a good idea but it's just too expensive, especially when the prevalence of death is so low.

'In this country, the feeling is that it would be too expensive and impractical to do it across the whole population, or at least to mandate it across the whole population,' said Euan Ashley, MD, PhD, assistant professor of cardiology and director of the Stanford Hypertrophic Cardiomyopathy Center.

The controversy reached a new head recently with research out of Italy, the only country to require such testing, showing that sudden death during competition has been virtually eliminated since mandatory testing began in 1982. Guidelines from the European Society of Cardiology and the International Olympic Committee recommending ECG testing have renewed a debate over the best way to screen athletes.

Despite the lack of mandatory requirements in the United States, some researchers at Stanford are convinced that more routine testing of athletes at all levels would save lives. They've set out to show that it can be done low-cost, conveniently and effectively. Equipment was purchased as part of the resources for the new Human Performance Lab but volunteerism is the credo of the day.

'So far, it hasn't cost us one dollar other than for the equipment,' said Froelicher, who coordinated a mass screening of 300 athletes on one recent weekend and completed ECGs on all 116 football players in just two hours. 'No one has refused testing. Coaches, trainers, athletes are all saying 'Why haven't we done this before?' I asked the athletes why they agreed to get the tests and the most consistent answer was because 'My mom wanted me to get one anyway.''

The screening started this fall with athletes invited but not required to participate. Froelicher said he would recommend to Stanford athletic officials that the screening become a routine practice.

Stanford athletic director Bob Bowlsby called the ECG screening 'a very effective preventive measure against sudden cardiac problems' but said he was awaiting an assessment from sports medicine staff before any decision on making the program permanent.

On a recent afternoon in the lobby of the Sports Medicine Clinic performance lab on the Stanford campus, cross-country runners drifted into the testing area.

'It's not a bad idea,' said runner Hari Mix, 21, of Virginia, who had completed his ECG stretched out on a bench with 10 sticky electrodes dotting his chest. The test took five minutes. 'We put our hearts through a lot of stress,' said Mix, a senior who runs 60 to 100 miles a week.

Sudden death in athletes is rare. About 300 deaths occur out of 10 million to 15 million athletes in organized sports nationwide. What researchers are looking for, when they examine the athletes' ECG results, is signs of a genetic defect called hypertrophic cardiomyopathy, or HCM, the most common cause of sudden death in young athletes. Other genetic syndromes can also be recognized.

Nationally, it's estimated that one out of every 500 people has HCM. The genetic defect causes a thickening of the heart muscle, which can block blood flow when the body is stressed. The first symptom can be death. If an athlete is found to have HCM, it's recommended they quit any strenuous exercise.

'We will undoubtedly find a case over the course of the next few years,' said Ashley, who started Stanford's HCM clinic two years ago. So far no cases have been found through the recent testing.

In response to a proposal earlier this year to mandate ECGs, the American Heart Association released a scientific statement indicating it would just be impractical and too expensive in the United States.

'First and foremost it would be difficult to imagine who would carry out the screening of 15 million people a year,' said Barry Maron, MD, director of the Hypertrophic Cardiomyopathy Center at the Minneapolis Heart Institute Foundation and chair of the AHA committee that wrote the paper. 'The AHA is not in the position of recommending the impossible. We just don't have the manpower to create a national program.'

He applauded Stanford's voluntary screening, but was wary about the staying power of most volunteer programs.

'It's deceptively more difficult than it appears in the beginning,' Maron said. Difficulty reading these advanced heart tests in athletes is one of the roadblocks that Ashley hopes the Stanford research will help overcome.

'About 60 percent of all athletes have abnormal ECGs by our strictest criteria but in most cases that doesn't indicate a medical problem,' said Ashley. Variations in the type and intensity of sports training creates variations in heart activity. Stanford is creating a database to record these variations and set up guidelines. 'In truth these young people we're testing are usually highly screened,' Froelicher said. 'The chance of us finding something is very low, but if we save one life it's worth it all. No question. We're definitely committed. It looks to me like it's going to be the standard.'

The program is coordinated by Stanford Sports Medicine and the Hypertrophic Cardiomyopathy Center.

By
Tracie White

Tracie White is a science writer for the medical school’s Office of Communication & Public Affairs.

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